The instant invention relates to a fleece hopper on a draw frame of the textile industry. The fleece hopper is located at the output of a textile draw frame.
In a draw frame, the fiber fleece delivered by the pair of delivery rollers is conveyed into the fleece hopper. There, the fiber fleece is gathered together and leaves the fleece hopper in the form of a fiber sliver. The fiber sliver is immediately conveyed on in a fiber sliver pipe leading to a sliver hopper which is located before a calendar roller pair. The calendar roller pair conveys the sliver into a depositing device which deposits the fiber sliver in the can. The draw frames RSB 851 (4135) and SB 851 (4131) of Rieter Ingolstadt are examples of such draw frames and the Operating Manual, August 1990, page 28, 4.4.3.2, FIGS. 7a, 7b for the RSB and SB draw frames explains these principles.
The fleece hopper is made of one massive piece of brass. As a result the production costs are relatively low. The fleece hopper is designed so that its width is greater than its height. It is provided with a centered cylindrical bore which acts as a hopper pipe. The hopper is adjusted to the center of the draw-off roller to ensure optimal entry of the fleece into the hopper bore. The adjustment requires different adjustment calibers for fleece hoppers with different hopper bore diameters (see RSB 851 (4135), SB 851 (4131), Operating Manual, August 1990, page 28, 4.4.3.2, FIG. 7b).
At the fiber sliver delivery speeds that are common today, intense friction of the fleece occurs at the deflection point between hopper side and hopper bore. The fleece is gathered together at the hopper side and is deflected into the bore. The result of the friction is material wear at the deflection point. This material wear is very detrimental since it affects the incoming fiber fleece adversely. Grooves are formed at the surface of the material, impeding entry. Replacement of the entire fleece hopper while the machine is stopped is required. No other measures for the elimination of wear have been found. Furthermore, when a new fleece hopper is installed, it is necessary to adjust it anew. This outlay of material and time is a disadvantage.